Method and Device for Direct-Contact Heat Exchange between a Fouling Liquid and a Cooling Fluid

ABSTRACT

A device and a method for conducting a heat exchange process is disclosed. A direct-contact heat exchanger is provided comprising a process inlet, a coolant inlet, and an interior surface. A process stream is provided to the process inlet to be cooled in the heat exchange process by direct contact with a coolant stream that is provided to the coolant inlet. The coolant stream comprises a liquid or a gas. The heat exchange process comprises a phase change from liquid to gas, a sensible heat transfer, or a combination thereof. The cooling process leads to chemical reactions, solids formation in the bulk phase, or a combination thereof. The use of the direct-contact heat exchanger minimizes such reactions on the interior surface. In this manner, the heat exchange process is conducted.

This invention was made with government support under DE-FE0028697 awarded by The Department of Energy. The government has certain rights in the invention.

FIELD OF THE INVENTION

This invention relates generally to the field of direct-contact heat exchange. More particularly, we discuss the process of direct contact heat exchange between fouling or corrosive liquids and cooling fluids.

BACKGROUND

The art of direct-contact heat exchange has been a part of the human experience since the discovery of cooking. More recently, direct-contact heat exchange is used in industry for warming and cooling gases, liquids, and solids. Direct-contact heat exchange is designed to maximize the contact surface area between the media exchanging heat. In general, this goal is accomplished by maximizing the amount of solid surface area of the exchanger. However, when the heat exchange process produces solids that can foul the flow paths of the exchanger, or reactive intermediates that can corrode or otherwise react with the surface of the exchanger, maximization of exchanger surface area is counter-productive. No effective system or method for conducting heat exchange of these fouling and reactive liquids is available.

U.S. Pat. No. 3,496,996 to Osdor teaches an apparatus for providing large surface area direct contact between a liquid and another fluid. The surface area of the exchanger is maximized to provide the most surface exchange between a liquid and a fluid. The present disclosure differs from this disclosure in that the amount of contact with the exchanger itself is maximized, rather than minimized. This disclosure is pertinent and may benefit from the methods disclosed herein and is hereby incorporated for reference in its entirety for all that it teaches.

U.S. Pat. No. 3,988,895 to Sheinbaum teaches power generation from hot brines. A multi-tray exchanger is utilized that maximizes heat exchange with the brine. The present disclosure differs from this disclosure in that the amount of contact with the exchanger itself is maximized, rather than minimized, in spite of the brine solution in use. This disclosure is pertinent and may benefit from the methods disclosed herein and is hereby incorporated for reference in its entirety for all that it teaches.

SUMMARY

A device and a method for conducting a heat exchange process is disclosed. A direct-contact heat exchanger is provided comprising a process inlet, a coolant inlet, and an interior surface. A process stream is provided to the process inlet to be cooled in the heat exchange process by direct contact with a coolant stream that is provided to the coolant inlet. The coolant stream comprises a liquid or a gas. The heat exchange process comprises a phase change from liquid to gas, a sensible heat transfer, or a combination thereof. The cooling process leads to chemical reactions, solids formation in the bulk phase, or a combination thereof. The use of the direct-contact heat exchanger minimizes such reactions on the interior surface. In this manner, the heat exchange process is conducted.

The cooling stream may comprise a liquid refrigerant that vaporizes by contact with the feed liquid, a gas refrigerant, or a combination thereof. The coolant inlet may comprise a pressure-drop device and the cooling stream, comprising a liquid refrigerant, is vaporized by passing through the pressure drop device into the direct-contact heat exchanger. The pressure-drop device may comprise a valve, turbine, nozzle, orifice, or combinations thereof.

Solids formation in the bulk phase may produce solid carbon dioxide, solid nitrogen oxide, solid sulfur dioxide, solid nitrogen dioxide, solid sulfur trioxide, solid hydrogen sulfide, solid hydrogen cyanide, water ice, solid hydrocarbons, precipitated salts, or combinations thereof.

The process stream may comprise soot, dust, minerals, microbes, wastewater, acids, bases, immiscible liquids, paper pulp, metal hydrides, solid carbon dioxide, solid nitrogen oxide, solid sulfur dioxide, solid nitrogen dioxide, solid sulfur trioxide, solid hydrogen sulfide, solid hydrogen cyanide, water ice, solid hydrocarbons, precipitated salts, other sulfides, other sulfates, chlorides, or combinations thereof.

The direct-contact heat exchanger may comprise a spray tower, bubble contactor, mechanically agitated tower, or combinations thereof.

The coolant inlet may comprise a gas distributor, bubble plate, sparger, nozzle, or combinations thereof.

The coolant stream may be soluble in the process stream, with the process stream pre-cooled to produce a pre-chilled process stream, and the coolant stream thus less soluble in the pre-chilled process stream. A temperature of the pre-chilled process stream may be near a freezing point of the pre-chilled process stream. A portion of the coolant stream may be dissolved into the product stream and the process stream further cooled to near a freezing point of the process stream, causing the coolant stream to become insoluble in the process stream, whereby the process stream is removed.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered limiting of its scope, the invention will be described and explained with additional specificity and detail through use of the accompanying drawings, in which:

FIG. 1 shows a method for conducting a heat exchange process.

FIG. 2 shows a cross-sectional view of a direct-contact heat exchanger for conducting a heat exchange process.

FIG. 3 shows a cross-sectional view of a direct-contact heat exchanger for conducting a heat exchange process.

FIG. 4 shows a cross-sectional view of a direct-contact heat exchanger for conducting a heat exchange process.

FIG. 5 shows a cross-sectional view of a direct-contact heat exchanger for conducting a heat exchange process.

FIG. 6 shows a cross-sectional view of a direct-contact heat exchanger for conducting a heat exchange process.

FIG. 7 shows an isometric cutaway view of a direct-contact heat exchanger for conducting a heat exchange process.

DETAILED DESCRIPTION

It will be readily understood that the components of the present invention, as generally described and illustrated in the Figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the invention, as represented in the Figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of certain examples of presently contemplated embodiments in accordance with the invention.

Referring to FIG. 1, a method for conducting a heat exchange process is shown at 100, as per one embodiment of the present invention. A direct-contact heat exchanger comprising a process inlet, a coolant inlet, and an interior surface is provided 101. A process stream is provided to the process inlet 102 to be cooled in the heat exchange process by direct contact with a coolant stream that is provided to the coolant inlet 103. The coolant stream comprises a liquid or a gas. The heat exchange process comprises a phase change from liquid to gas, a sensible heat transfer, or a combination thereof, and the cooling process leads to chemical reactions, solids formation in the bulk phase, or a combination thereof. The use of the direct-contact heat exchanger minimizes such reactions on the interior surface. In this manner, the heat exchange process is conducted.

Referring to FIG. 2, a cross-sectional view of a direct-contact heat exchanger for conducting a heat exchange process is shown at 200, as per one embodiment of the present invention. Direct-contact heat exchanger 202 is provided, comprising process inlet 204, coolant inlet 206, interior surface 208, process outlet 218, and coolant outlet 220. Process stream 210 is provided to process inlet 204. The coolant stream, liquid refrigerant 212, is provided to coolant inlet 206. Liquid refrigerant 212 cools process stream 210 to form cooled process stream 214 by direct contact in a cooling process comprising a phase change from liquid to gas and a sensible heat transfer, producing warmed coolant stream 216. The cooling process leads to chemical reactions, solids formation in the bulk phase, or a combination thereof. The use of direct-contact heat exchanger 202 minimizes such reactions on interior surface 208. Cooled process stream 214 leaves through process outlet 218 while warmed coolant stream 216 leaves through coolant outlet 220.

Referring to FIG. 3, a cross-sectional view of a direct-contact heat exchanger for conducting a heat exchange process is shown at 300, as per one embodiment of the present invention. Bubble contactor 302 is provided, comprising process inlet 304, bubble plate 306, interior surface 308, process outlet 318, and coolant outlet 320. Isopentane stream 310 is provided to process inlet 304, isopentane stream 310 comprising dissolved carbon dioxide. The coolant stream, liquid nitrogen stream 312, is provided through bubble plate 306. Liquid nitrogen stream 312 cools isopentane stream 310 to form cooled isopentane stream 314 by direct contact in a cooling process comprising a phase change from liquid to gas and a sensible heat transfer, producing warmed nitrogen stream 316. The cooling process leads to solid carbon dioxide formation in the bulk phase. The use of direct-contact heat exchanger 302 minimizes the production of solid carbon dioxide on interior surface 308. Cooled isopentane stream 314 leaves through process outlet 318 while warmed nitrogen stream 316 leaves through coolant outlet 320.

Referring to FIG. 4, a cross-sectional view of a direct-contact heat exchanger for conducting a heat exchange process is shown at 400, as per one embodiment of the present invention. Bubble contactor 402 is provided, comprising process inlet 404, bubble plate 406, interior surface 408, process outlet 418, and coolant outlet 420. Brine stream 410 is provided to process inlet 404, brine stream 410 comprising dissolved salts. The coolant stream, liquid methane stream 412, is provided through bubble plate 406. Liquid methane stream 412 cools brine stream 410 to form cooled brine stream 414 by direct contact in a cooling process comprising a phase change from liquid to gas and a sensible heat transfer, producing warmed methane stream 416. The cooling process leads to precipitation of salts in the bulk phase. The use of direct-contact heat exchanger 402 minimizes the production of salts on interior surface 408. Cooled brine stream 414 leaves through process outlet 418 with the salts entrained, while warmed methane stream 416 leaves through coolant outlet 420.

Referring to FIG. 5, a cross-sectional view of a direct-contact heat exchanger for conducting a heat exchange process is shown at 500, as per one embodiment of the present invention. Direct-contact heat exchanger 502 is provided, comprising process inlet 504, nozzles 506, interior surface 508, process outlet 518, and coolant outlet 520. Liquid stream 510 is provided to process inlet 504, liquid stream 510 comprising metal hydrides. The coolant stream, cold argon stream 512, is provided through nozzles 506. Cold argon stream 512 cools liquid stream 510 to form cooled liquid stream 514 by direct contact in a cooling process comprising a sensible heat transfer, producing warmed argon stream 516. The use of direct-contact heat exchanger 502 minimizes metal hydrides reacting with or because of interior surface 508. Cooled liquid stream 514 leaves through process outlet 518, while warmed argon stream 516 leaves through coolant outlet 520.

Referring to FIG. 6, a cross-sectional view of a direct-contact heat exchanger for conducting a heat exchange process is shown at 600, as per one embodiment of the present invention. Direct-contact heat exchanger 602 is provided, comprising process inlet 604, coolant inlet 606, coolant valve 622, interior surface 608, process outlet 618, and coolant outlet 620. Slurry stream 610 is provided to process inlet 604, slurry stream 610 comprising solid acid gases. The coolant stream, liquid ethane stream 612, is provided through nozzles 606. Liquid ethane stream 612 cools slurry stream 610 to form cooled slurry stream 614 by direct contact in a cooling process comprising a phase change from liquid to gas and a sensible heat transfer, producing warmed ethane stream 616. Zoomed in view 624 shows the interface between the vaporizing ethane stream and slurry stream 610. The use of direct-contact heat exchanger 602 minimizes deposit of solid acid gases on interior surface 608. Cooled slurry stream 614 leaves through process outlet 618, while warmed ethane stream 616 leaves through coolant outlet 620. Solid acid gases comprise solid forms of carbon dioxide, nitrogen oxide, sulfur dioxide, nitrogen dioxide, sulfur trioxide, hydrogen sulfide, and hydrogen cyanide.

Referring to FIG. 7, an isometric cutaway view of a direct-contact heat exchanger for conducting a heat exchange process is shown at 700, as per one embodiment of the present invention. Direct-contact heat exchanger 702 is provided, comprising process inlets 704, coolant inlet 706, interior surface 708, process outlet 718, and coolant outlet 720. Process stream 710 is provided to process inlets 704, process stream 710 comprising chlorides. Coolant stream 712 is provided through coolant inlet 706. Coolant stream 712 cools process stream 710 to form cooled process stream 714 by direct contact in a cooling process comprising a sensible heat transfer, producing warmed coolant stream 716. The use of direct-contact heat exchanger 702 minimizes the reaction of chlorides with interior surface 708. Cooled process stream 714 leaves through process outlet 718, while warmed coolant stream 716 leaves through coolant outlet 720.

In some embodiments, the cooling stream comprises a liquid refrigerant that vaporizes by contact with the feed liquid, a gas refrigerant, or a combination thereof.

In some embodiments, the coolant inlet comprises a pressure-drop device and the cooling stream, comprising a liquid refrigerant, is vaporized by passing through the pressure drop device into the direct-contact heat exchanger, and wherein the pressure-drop device comprises a valve, turbine, nozzle, orifice, or combinations thereof.

In some embodiments, solids formation in the bulk phase produces solid carbon dioxide, solid nitrogen oxide, solid sulfur dioxide, solid nitrogen dioxide, solid sulfur trioxide, solid hydrogen sulfide, solid hydrogen cyanide, water ice, solid hydrocarbons, precipitated salts, or combinations thereof.

In some embodiments, the process stream comprises soot, dust, minerals, microbes, wastewater, acids, bases, immiscible liquids, paper pulp, metal hydrides, solid carbon dioxide, solid nitrogen oxide, solid sulfur dioxide, solid nitrogen dioxide, solid sulfur trioxide, solid hydrogen sulfide, solid hydrogen cyanide, water ice, solid hydrocarbons, precipitated salts, other sulfides, other sulfates, chlorides, or combinations thereof.

In some embodiments, the direct-contact heat exchanger comprises a spray tower, bubble contactor, mechanically agitated tower, or combinations thereof.

In some embodiments, the coolant inlet comprises a gas distributor, bubble plate, sparger, nozzle, or combinations thereof.

In some embodiments, the coolant stream is soluble in the process stream, the process stream is pre-cooled to produce a pre-chilled process stream, and the coolant stream is less soluble in the pre-chilled process stream. In some embodiments, a temperature of the pre-chilled process stream is near a freezing point of the pre-chilled process stream. In some embodiments, a portion of the coolant stream is dissolved into the product stream and the process stream is further cooled to near a freezing point of the process stream, causing the coolant stream to become insoluble in the process stream, whereby the process stream is removed.

In some embodiments, the coolant inlet comprises a material that inhibits adsorption of gases, prevents deposition of solids, or a combination thereof. In some embodiments, this material comprises ceramics, polytetrafluoroethylene, polychlorotrifluoroethylene, natural diamond, man-made diamond, chemical-vapor deposition diamond, polycrystalline diamond, or combinations thereof.

In some embodiments, the liquid refrigerant comprises ethane, methane, propane, R14, nitrogen, oxygen, argon, helium, xenon, other light gases, aliphatic hydrocarbons, aromatic hydrocarbons, other refrigerants, or combinations thereof. In some embodiments, the gas refrigerant comprises ethane, methane, propane, R14, nitrogen, oxygen, argon, helium, xenon, other light gases, aliphatic hydrocarbons, aromatic hydrocarbons, other refrigerants, or combinations thereof. 

1. A method for conducting a heat exchange process comprising: providing a direct-contact heat exchanger comprising a process inlet, a coolant inlet, and an interior surface; and, providing a process stream to the process inlet to be cooled in the heat exchange process by direct contact with a coolant stream that is provided to the coolant inlet, the coolant stream comprising a liquid or a gas, wherein the heat exchange process comprises a phase change from liquid to gas, a sensible heat transfer, or a combination thereof, and the cooling process leads to chemical reactions, solids formation in a bulk phase, or a combination thereof, the use of the direct-contact heat exchanger minimizing such reactions on the interior surface; whereby the heat exchange process is conducted.
 2. The method of claim 1, wherein the cooling stream comprises a liquid refrigerant that vaporizes by contact with the feed liquid, a gas refrigerant, or a combination thereof.
 3. The method of claim 1, wherein the coolant inlet comprises a pressure-drop device and the cooling stream, comprising a liquid refrigerant, is vaporized by passing through the pressure drop device into the direct-contact heat exchanger, and wherein the pressure-drop device comprises a valve, turbine, nozzle, orifice, or combinations thereof.
 4. The method of claim 1, wherein solids formation in the bulk phase produces solid carbon dioxide, solid nitrogen oxide, solid sulfur dioxide, solid nitrogen dioxide, solid sulfur trioxide, solid hydrogen sulfide, solid hydrogen cyanide, water ice, solid hydrocarbons, precipitated salts, or combinations thereof.
 5. The method of claim 1, wherein the process stream comprises soot, dust, minerals, microbes, wastewater, acids, bases, immiscible liquids, paper pulp, metal hydrides, solid carbon dioxide, solid nitrogen oxide, solid sulfur dioxide, solid nitrogen dioxide, solid sulfur trioxide, solid hydrogen sulfide, solid hydrogen cyanide, water ice, solid hydrocarbons, precipitated salts, other sulfides, other sulfates, chlorides, or combinations thereof.
 6. The method of claim 1, wherein the direct-contact heat exchanger comprises a spray tower, bubble contactor, mechanically agitated tower, or combinations thereof.
 7. The method of claim 1, wherein the coolant inlet comprises a gas distributor, bubble plate, sparger, nozzle, or combinations thereof.
 8. The method of claim 1, wherein the coolant stream is soluble in the process stream, the process stream is pre-cooled to produce a pre-chilled process stream, and the coolant stream is less soluble in the pre-chilled process stream.
 9. The method of claim 8, wherein a temperature of the pre-chilled process stream is near a freezing point of the pre-chilled process stream.
 10. The method of claim 8, wherein a portion of the coolant stream is dissolved into the product stream and the process stream is further cooled to near a freezing point of the process stream, causing the coolant stream to become insoluble in the process stream, whereby the process stream is removed.
 11. A direct-contact heat exchanger comprising: a process inlet, a coolant inlet, and an interior surface, wherein: a process stream is provided to the process inlet to be cooled and a coolant stream is provided to the coolant inlet to cool the process stream by direct contact, the coolant stream comprising a liquid or a gas; the coolant stream cools the process stream by a cooling process comprising a phase change from liquid to gas, a sensible heat transfer, or a combination thereof; the cooling process leads to chemical reactions, solids formation in a bulk phase, or a combination thereof, the use of the direct-contact heat exchanger minimizing such reactions on the interior surface.
 12. The device of claim 11, wherein the cooling stream comprises a liquid refrigerant that vaporizes by contact with the feed liquid, a gas refrigerant, or a combination thereof.
 13. The device of claim 11, wherein the coolant inlet comprises a pressure-drop device and the cooling stream, comprising a liquid refrigerant, is vaporized by passing through the pressure drop device into the direct-contact heat exchanger, and wherein the pressure-drop device comprises a valve, turbine, nozzle, orifice, or combinations thereof.
 14. The device of claim 11, wherein solids formation in the bulk phase produces solid carbon dioxide, solid nitrogen oxide, solid sulfur dioxide, solid nitrogen dioxide, solid sulfur trioxide, solid hydrogen sulfide, solid hydrogen cyanide, water ice, solid hydrocarbons, precipitated salts, or combinations thereof.
 15. The device of claim 11, wherein the process stream comprises soot, dust, minerals, microbes, solid carbon dioxide, solid nitrogen oxide, solid sulfur dioxide, solid nitrogen dioxide, solid sulfur trioxide, solid hydrogen sulfide, solid hydrogen cyanide, water ice, solid hydrocarbons, precipitated salts, or combinations thereof.
 16. The device of claim 11, wherein the direct-contact heat exchanger comprises a spray tower, bubble contactor, sieve tray column, bubble tray column, baffle tray column, mechanically agitated tower, perforated pipe, air-sparged hydrocyclone, nozzle-injected hydrocyclone, or combinations thereof.
 17. The device of claim 11, wherein the coolant inlet comprises a gas distributor, bubble plate, sparger, nozzle, or combinations thereof.
 18. The device of claim 11, wherein the coolant stream is soluble in the process stream, the process stream is pre-cooled to produce a pre-chilled process stream, and the coolant stream is less soluble in the pre-chilled process stream.
 19. The device of claim 18, wherein a temperature of the pre-chilled process stream is near a freezing point of the pre-chilled process stream.
 20. The device of claim 18, wherein a portion of the coolant stream is dissolved into the product stream and the process stream is further cooled to near a freezing point of the process stream, causing the coolant stream to become insoluble in the process stream, whereby the process stream is removed. 